Ground-clamp.



v w. H. PRICE. GROUND CLAMP.

APPLICATION FILED JULY 15, 1913.

Patented Apr. 13, 11915.

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T all whom z't-may concern lBe itpknown that ll, WALTER H. PRICE, a citizen of the United States, residing at Moores, county of Delaware, and State of Pennsylvania, have invented a certain new and useful Ground-Clamp, of which the following is a specification.

This inventhm relates to ground clamps and is particularly directed to the provision of an improved type thereof, which is calculated for use in electrically connecting a conduit containing electric wiring with an ordinary water pipe.

The invention has for its principal objects to provide a ground clamp adapted to efi'ect certain specific results combined with simplicity of construction, and ease with which it may be set up and non-liability of breakage or disconnection when installed.

A further object of the present invention is to provide a ground clamp, which may be cheaply manufactured and sold and which is eflicient for the purposes intended.

Other and further objects of the invention relate to the providing of general details of construction and arrangement of parts as will hereinafter more fully appear.

The invention consists of the improveinents hereinafter described and finally claimed.

The nature, characteristic features and scope of the invention Wlll be more fully trating the manner of connecting an elec tric conduit and a water pipe together by employing the ground clamp of the invention, Fig. 2, is a. top or plan view of Fig. 1, Fig. 3, is a top or plan view of Fig. 5, but drawn on a reduced scale, Fig. 4, is a view in cross section taken upon the line H of Fig. 5, and drawn to a reduced scale, and Fig. 5, is a central sectional view of. the ground clamp of the invention.

Referring to the drawings 1, designates an ordinary metallic pipe or conduit containing electrical wiring 2, and 3, designates an ordinary metallic water pipe. "in elee trical wiring of houses and the like, it is customary to electrically connect the core duits containing the wiring with a water pipe, so that, in the case of defective wiring, leakage of current to the-conduit is caused specification a was man. Patented Apr, as, was.

Application filed July 15, 1913. Serial No. 779,1421.

to find its way to the water pipe and thence to the ground. The ground clamp of the present invention is specifically designed to facilitate the betterment of this class of work and render more positive said connections.

As shown in the drawings, the ground clamp comprises separable metallic plates 4., and 5, which plates have opposing faces. As clearly illustrated, one of these plates, and in the specific instance shown, the outer plate 4, is provided with a flat face 6, and the plate 5, has formed thereon concaved portions 7, upon the face adjacent said fiat plate and has formed thereon convexed portions 8, upon the opposite face of said plate. The concave-convex formation of the plate 5, forms grooves 9, which extend laterally or crosswise of the ground clamp and are lisposed relatively central. of the same. The plate l, has an uthreaded opening 10, which passes through the central portion thereofv and the plate 5, has a screw threaded opening 11, which registers with the opening 10. Passing through the openings 10, and 11, of said plates, is a screw 12, for securing the ground clamp to desired position upon the conduit 1, or water pipe 3. The ends of the plate 4, each have an unthreaded opening 13, therethrough and the plate 5, has screw-threaded openings 14:, therethrough, which openings 13, and 14:, regib ter with one another. Screws 15, are accommodated by said openings 13, and 14, whereby the ends of said plates may be clamped together independently of the attaching screw 12. By this arrangement and construction of. parts, conductors passing through the grooves 9, may be clamped between said plates by the screws 15, before the ground clamp has been screwed to place. In practice good results have been obtained by forming electrical connection between a conduit 1, and water pipe 3, as shown in Figs. .1, and 2. As there illustrated, a wire 16, uslially copper, is passed through one of the grooves 9, and looped around the conduit 1, for two turns and the free end of the same passed through the other groove of the same clamp. The screws 15-, are then tightened, thereby clamping the ends of the wire it, to place illhereu'pon the screw 12, is operated to tighten the wire upon the conduit. The same operation is repeated with respect to the ground clamp upon the water pipe 3, and a conductor 17, utilized for con- .clamp as a whole.

necting electrically said ground clamps together. In this connection, it may be stated, that the convexed parts 8, of the plate 5,

abut against the pipe or conduit sides and serve as good seating points for the ground In other Words, as the surface of the conduit or pipe is cylindrical, the said convexed portions 8, form two contact points in contradistinction to a single contact point, as would be the case if the inner surface of the plate 5, was fiat. In practice the parts of the ground clamp are tinned or copper plated in order to prevent corrosion of said parts, the advantages of which Will be readily apparent.

What I claim is:

1. In a ground wire clamp, separable I plates having opposing faces of which one is fiat and the other is provided with spaced concave-convex parts for conduit clamping wire reception and for conduit periphery engagement respectively, a wire passing through one of said grooves and looped around a conduit for at least two turns and the free end thereof passed through the other of said'grooves, a central screw passing through said plates for securing the same with respect to a conduit and other screws at the plate ends for independently securing the wire ends between said plates.

2. A device of the class described comprising a pair of separable thin metallic rectangular plates of the same thickness of metal having opposing faces of which one plate is flat and of which the other plate has formed thereon concaved conduit clamping wire receiving portions upon the face adjacent said flat plate and convexed portions upon the opposite face thereof for conduit periphery engagement said so formed portions being arranged centrally of the plate and disposed transversely thereof, a screw passing through said plate and between said concavo-convex parts for securing the plates to desired position and other screws passing through the extreme ends of said plates for independently retaining the clamping wire ends between said plates.

. In testimony whereof, I have hereunto signed my name.

WALTER H. PRICE. Witnesses:

Roe'r. F.- BONNER, CHAS. HARDMAN. 

